After dry firing and using my Lyman Digital Scale to check my trigger pull on my 617 I was getting reading of over the scale. A lot were in the 10 pound range which is non typical on this gun.
My normal trigger pull is set at around 7 pounds on average.
I opened the cylinder and was getting hits on another corner of the rimmed cases. I thought it might be timing but after one cylinder turn I couldn't open the cylinder up. I finally coached it open and a small piece of metal fell out.
Turns out my firing pin had broken. It's an extended firing pin and I know they occasionally break so I took out one of my spares and installed a new one. This solved the problem.
Back to a 7 pound trigger pull so I'm happy.